It's Something in the Water

0 Comments | Insight on the News, Jan 29, 2001 | by John Elvin

The environmental-activist group says its studies indicate that as many as 56 million Americans drink water with unsafe levels of arsenic, while EPA's own data indicate that about 34 million Americans are exposed to arsenic in their water, though apparently not at threatening levels.

Knowledge of the natural presence of arsenic in water is nothing new, at least among experts, and allegedly tolerable levels have been known for more than 50 years and regulated since 1975. But more recently science has raised concerns about arsenic's role in skin, lung and bladder cancers. The National Academy of Sciences says it also may play a role in kidney and liver cancers, harm the nervous system and heart and possibly cause birth defects.

Although arsenic certainly is something to worry about, better grab a long string of worry beads because there's lots more. The list could run to more than 100 substances that, in sufficient quantity, are known or suspected as being harmful to humans.

A few of these substances include barium, benzene, chloroform, heptachlor, lead, mercury, radon, sulfate, tetrachloroethylene and xylene -- and there are plenty more. Some substances that occur naturally can be considered contaminants at higher levels. Sodium can be dangerous to some people. Among the effects attributed to these substances are cancer, tumors, bronchial problems, liver and kidney damage, gastrointestinal problems, nausea, coma and, of course, death.

How difficult will it be to fix the infrastructure problems? Myron J. Coplan, a chemical engineer who worked with Dartmouth College professor Roger Masters on studies relating to silicofluoride, puts the problem in perspective. "The Mississippi River is nearly 2,000 miles long. In northern Minnesota, the river water may be pure enough to drink, but water-treatment plants undoubtedly use some kind of disinfectant, likely chlorine, to be sure the water is sterilized," he tells Insight. "Probably as much as 90 percent of this sterilized water is returned to the river a few miles downstream from where it was taken in. But, it goes back into the river in the form of sewage."

"So," Coplan continues, "the next town downstream does a little more disinfecting, and so on until it gets to the Delta." At that point, he suggests, "the river has collected a load of chlorinated low-molecular-weight hydrocarbons," a reference to substances such as chloroform that are considered "toxic and carcinogenic." Cleaning that up is a process that would have to begin all the way back upstream in Minnesota.

Most municipalities test for contaminants at least to the extent required by the EPA. But it's interesting to note that when the EPA asked the states for information on arsenic levels in their water supplies, half didn't respond. Possibly they feel overburdened with such requests: A complete assessment of water quality is due to be supplied to EPA by each state by 2003 under the terms of the federal Safe Drinking Water Act. This assessment is to include mapping sources of water, inventorying potential contamination problems and telling the public what was found.